>>If the word "investment" is meant to include an investment in a>>future beyond their own lifetimes, then I would agree.

>Immortality is a good investment (if rather selfish).

Immortality would be a wonderful investment, but having children
is not immortality. (Webster's "unending existance") Reproduction
is good for the culture, but not especially good for the individual,
in modern life. Having some percentage of your genes carried on
into the distant future doesn't seem to be sufficient compensation
for multiplying responsibilities, reducing life expectancy (for men)
and, in childbirth, for women), and complicating one's lifestyle.
The reasons most (>50%) people experess for having children are much
more simple and less esoteric than immortality.